1. Field of the Invention
The present invention broadly concerns a forming panel used in forming wall structures of hardenable concrete, whereby multiple panels may be placed in adjacency and in opposition for receiving and supporting the concrete pour therebetween. More particularly, it is concerned with a concrete forming panel which includes a flexible barrier positioned adjacent and preferably aligned with a margin on the forming panel such as a perimeter edge or on an interior edge to inhibit the flow of the concrete mix therepast.
2. Description of the Prior Art
The formation of building walls, foundations and other wall structures from poured concrete after curing is well known and the forms used for holding the concrete fall into two general categories. Forming walls may be made of site-built forms, typically of plywood, and are used only once before being discarded, or of reusable forming panels, typically of wood, steel or aluminum or combinations thereof, which panels may be fastened together and then removed from the hardened concrete wall for reuse. While these reusable forming panels are typically of a greater initial cost, their ability to be repeatedly used more than compensates for the initial expense.
The reusable forming panels typically have a face plate supported by a frame and are joined together in adjacency (essentially side-by-side or angled) to provide a form wall, and two form walls oppose one another to receive the concrete therebetween. Each forming panel may have a number of relieved areas along the side to receive tie bars for connecting the opposing form walls. Where the panels meet along their perimeters, small gaps are present, especially in the relieved areas not occupied by a tie bar. Moreover, the panels may have interior holes or openings which are penetrated interiorly of the perimeter of the forming panel by tie bars, rods or the like, and there are similar gaps between the tie bars and the surrounding forming panel. The concrete is mixed with water to make it flowable and ready to pour, the concrete mix typically including water, fine particles of mortar and sand, and aggregate such as gravel. In the gaps along the perimeter of the forming panels and where there are openings on the interior of the forming panel, water and fine particles of sand and mortar of the wet concrete will typically migrate from the concrete pour during curing. As a result, the appearance of the cured and hardened concrete opposite these gaps will be discolored, and will typically have significant raised ridges and be pitted rather than smooth as appears along the face of the forming panel. The large ridges and the pitted area along the face may affect not only the appearance but also the performance of the concrete wall over time.
These problems are significantly ameliorated by the concrete forming panel provided with a flexible barrier in accordance with the present invention. By the provision of a flexible barrier along and proximate to one or more margins in the forming panel which engage flowable concrete during curing, such as the face plate and frame, a substantial reduction in the loss of fine mortar particles and water is achieved. This results in a finished wall surface with substantial reduction of discoloration and pitting, even in the relieved tie bar passage area or interior openings. The flexible barrier serves as a gasket which yields for variations in the size of the gaps as well as permitting tie bars and other forming accessories to abut and pass thereby, and stands up to rugged use environments. Moreover, when the panel has an opening within the perimeter of the face plate and rails of the frame, by providing an interior margin provided with such a barrier within the perimeter of the forming panel, the forming panel hereof substantially reduces the problem of large ridges and pitting where tie bars and other forming hardware must pass through openings in the frame inside of the perimeter. An additional benefit is reduced seepage of moisture into and through the hardened wall structure.
In greater detail, the forming panel with flexible barrier along one or more of its margins broadly includes a form configured to receive a pour of a flowable concrete mix in supporting relationship thereagainst, the forming panel in a face plate typically of aluminum and a frame also of aluminum or steel having at least one siderail. The frame typically includes parallel and spaced apart, opposed endrails, siderails in spaced relationship and extending parallel thereto, and crossbraces, end reinforcements and gusset plates. The rails have exposed edges and face plate edges, with elongated grooves provided in the rails (both endrails and siderails) on the exterior side thereof. Flexible barriers acting as gaskets, preferably of filaments such as brush strips, are received in the grooves to impede the migration of water and fine particles of the concrete mix therepast as the barriers engage opposing parts of the forming panel or adjacent forming panels. The brush fibers of the brush strips are preferably oriented at an angle toward the concrete-receiving surface of the face plate and extend beyond the outer surface of the frame, whereby when the barrier is engaged by another component of the forming panel, a tie bar, another forming panel or an opposing barrier, the brush fibers project toward the concrete mix in the pour and the face plate rather than away to minimize the amount of water and fine mortar and sand particles of the mix carried into the gap between forms. Alternately, or in addition to the flexible barrier positioned near the perimeter margin of the forming panel, openings within the face plate may have flexible barriers mounted in proximity. The openings within the face plate may be substantially covered by a shiftable door which may be hinged, so that when there is no need to pass a tie bar therethrough, the door may be sealed. On the other hand, opening the door greatly facilitates placement and coupling of a tie bar to the forming panel, and closing of the door still permits a tie bar to pass thereby. The flexible barrier may be provided on either the door or a reinforcing enclosure around the opening, or both. The door is preferably hingably mounted to the reinforcing enclosure and a closure member provided to hold the door closed. A narrow gap may be provided between the door and the face plate when the door is in a closed position, to thereby permit the tie bar to pass therethrough when the door is closed, the barrier element helping to seal the gap.
As a result, forms are provided which substantially reduce the amount of discoloration and pitting in the finished wall surface, minimize the formation of ridges of material migrating into the gaps between forms, and provide an improved finished concrete surface while remaining rugged in use. These and other advantages will be appreciated by those skilled in the art with reference to the drawings and description which follow.